

/*
 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   - Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   - Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *
 *   - Neither the name of Oracle nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

import static java.nio.file.LinkOption.NOFOLLOW_LINKS;
import static java.nio.file.StandardWatchEventKinds.ENTRY_CREATE;
import static java.nio.file.StandardWatchEventKinds.ENTRY_DELETE;
import static java.nio.file.StandardWatchEventKinds.ENTRY_MODIFY;
import static java.nio.file.StandardWatchEventKinds.OVERFLOW;

import java.beans.XMLDecoder;
import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.net.MalformedURLException;
import java.nio.file.FileSystems;
import java.nio.file.FileVisitResult;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.SimpleFileVisitor;
import java.nio.file.WatchEvent;
import java.nio.file.WatchKey;
import java.nio.file.WatchService;
import java.nio.file.attribute.BasicFileAttributes;
import java.util.HashMap;
import java.util.Map;

import GUI.Configuration;
import GUI.EntryConfig;

/**
 * Example to watch a directory (or tree) for changes to files.
 */

public class WatchDir implements Runnable{

    private WatchService watcher;
    private Map<WatchKey,Path> keys;
    private static boolean start = true;
    private static boolean pause = false;
    private boolean trace = false;
    public static WatchDir serviceInstance = new WatchDir();
    private static Path db;
    private static StartTag tag;
    //private StartTag st;
    
    public void setDir(Path p){
    	db = p;
    }
    
    public void setTag(StartTag t){
    	tag=t;
    }
    
    @SuppressWarnings("unchecked")
    static <T> WatchEvent<T> cast(WatchEvent<?> event) {
        return (WatchEvent<T>)event;
    }

    @Override
    public void run() {
    	//Path db = Paths.get("c:/dropbox");//default--->>need to change
    	
    	try {
			initial();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
    
	    processEvents();
    }
 
    /**
     * Register the given directory with the WatchService
     */
    private void register(Path dir) throws IOException {
        WatchKey key = dir.register(watcher, ENTRY_CREATE, ENTRY_DELETE, ENTRY_MODIFY);
        if (trace) {
            Path prev = keys.get(key);
            if (prev == null) {
            	System.out.println("register: "+dir+"\n");
            } else {
                if (!dir.equals(prev)) {
                    System.out.println("update: "+prev+" -> "+dir+"\n");
                }
            }
        }
        keys.put(key, dir);
    }

    /**
     * Register the given directory, and all its sub-directories, with the
     * WatchService.
     */
    private void registerAll(final Path start) throws IOException {
        // register directory and sub-directories
        Files.walkFileTree(start, new SimpleFileVisitor<Path>() {
            @Override
            public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs)
                throws IOException
            {
                register(dir);
                return FileVisitResult.CONTINUE;
            }
        });
    }
    
    private void initial() throws IOException {
    	this.watcher = FileSystems.getDefault().newWatchService();
        this.keys = new HashMap<WatchKey,Path>();
    	System.out.println("Scanning "+db+" ...\n");
    	registerAll(db);
    	System.out.println("Done.");
    	this.trace = true;
    }

    /**
     * Creates a WatchService and registers the given directory
     * @throws IOException 
     */
    public WatchDir(){
    	
    }

    /**
     * Process all events for keys queued to the watcher
     */
    private void processEvents() {
    	start = true;
    	//st = new StartTag(tag);
        while(start) {
            // wait for key to be signaled
            WatchKey key;
            try {
                key = watcher.take(); 
                
            } catch (InterruptedException x) {
            	if(!start)
                 	continue;
            	if(pause){	//call wait function of thread
        			synchronized (this) {
        				try { 
        					wait();
        				} catch (InterruptedException e) {}
        			}
        		}
                continue;
            }

            Path dir = keys.get(key);
            if (dir == null) {
                System.err.println("WatchKey not recognized!!");
                continue;
            }

            for (WatchEvent<?> event: key.pollEvents()) {
                @SuppressWarnings("rawtypes")
				WatchEvent.Kind kind = event.kind();
      
                // TBD - provide example of how OVERFLOW event is handled
                if (kind == OVERFLOW) {
                    continue;
                }

                // Context for directory entry event is the file name of entry
                WatchEvent<Path> ev = cast(event);
                Path name = ev.context();
                Path child = dir.resolve(name);

                // print out event
                System.out.println(event.kind().name()+": "+child);
                
                // if directory is created, and watching recursively, then
                // register it and its sub-directories
                if (kind == ENTRY_CREATE) {
                	
                	try {
						tag.createTag(child);
					} catch (ClassNotFoundException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					} catch (MalformedURLException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					} catch (InstantiationException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					} catch (IllegalAccessException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					}
                    try {
                        if (Files.isDirectory(child, NOFOLLOW_LINKS)) {
                            registerAll(child);
                        }
                    } catch (IOException x) {
                        // ignore to keep sample readable
                    }
                }
                else if(kind == ENTRY_DELETE)
                	tag.deleteTag(child);
                else if(kind == ENTRY_MODIFY);
            }

            // reset key and remove from set if directory no longer accessible
            boolean valid = key.reset();
            if (!valid) {
                keys.remove(key);

                // all directories are inaccessible
                if (keys.isEmpty()) {
                    break;
                }
            }
        }
     
    }
    
  //Stops this service instance
    public void stopping() {
       start = false;
    }
    
    //Pause this service instance
    public void pause() {
        pause = true;
     }
    
    //Resuming to service instance
    public void resuming() {
    	pause = false;
     }


    static void usage() {
        System.err.println("usage: java WatchDir [-r] dir");
        System.exit(-1);
    }

   /* public static void main(String[] args) throws IOException {
        // parse arguments
        //if (args.length == 0 || args.length > 2)
          //  usage();
        boolean recursive = true;
      //  int dirArg = 0;
     //   if (args[0].equals("-r")) {
         //   if (args.length < 2)
           //     usage();
          //  recursive = true;
           // dirArg++;
       // }

        // register directory and process its events
        Path dir = Paths.get("c:/dropbox"/*args[dirArg]*///);
   //     new WatchDir(dir, recursive).processEvents();
  //  }*/
}
